Embedded animation example

This notebook demonstrates how to generate simple embedded animations in Jupyter.

Adapted from: http://louistiao.me/posts/notebooks/embedding-matplotlib-animations-in-jupyter-as-interactive-javascript-widgets/

import numpy as np
import matplotlib.pyplot as plt

from matplotlib import animation, rc
from IPython.display import HTML

First example is a simple line plot

First initialize a figure, axis, and line object

fig, ax = plt.subplots()

ax.set_xlim(( 0, 2))
ax.set_ylim((-2, 2))

line, = ax.plot([], [], lw=2)

define an init function. This will be called once to initialize the plot.

def init():
    line.set_data([], [])
    return (line,)

define an animate function. This will be called once per frame

def animate(i):
    x = np.linspace(0, 2, 1000)
    y = np.sin(2 * np.pi * (x - 0.01 * i))
    line.set_data(x, y)
    return (line,)

define the animation itself

anim = animation.FuncAnimation(fig, animate, init_func=init,
                               frames=100, interval=20, 
                               blit=True)

Render the animation as an html5 video. This requires ffmpeg to be installed.

HTML(anim.to_html5_video())

Render the animation as an embedded javascript animation. This does not require ffmpeg and is interactive, which is nice.

HTML(anim.to_jshtml())

Once Loop Reflect

Repeat for a 3 dimensional (x, y, z) heatmap/image

Define a function to generate an array

def make_array(exponent):
    x = np.arange(0, 5, 0.01)
    y = np.arange(0, 5, 0.01)
    xx, yy = np.meshgrid(x, y, sparse=True)

    return np.sin(xx**exponent + yy**exponent)

Intitialize a figure, axis, and image object

fig, ax = plt.subplots()

im = ax.imshow(make_array(2))

define our init and animate functions, just like above

def init():
    im.set_data(make_array(0))
    return (im,)

def animate(i):
    F =50
    im.set_data(make_array(i/F))
    ax.set_title('i = {}, function_input = {}'.format(i, i/F))
    return (im,)

Define our animation object

anim = animation.FuncAnimation(fig, animate, init_func=init,
                               frames=200, interval=50, 
                               blit=True)

Build an html5 video

HTML(anim.to_html5_video())

Generate a javascript animation

HTML(anim.to_jshtml())

Once Loop Reflect